The EOS-1Ds Mark III is the seventh Canon professional EOS-1D series digital SLR, although only the third of the 's' suffix sub-category which indicates a full frame sensor. Three years after the last EOS-1Ds, the Mark II, the Mark III pushed digital SLR resolution over the twenty megapixel barrier with specifically twenty-one-point-one million pixels (5616 x 3744) on its 36 x 24 mm (full 35 mm frame) sensor.

The Mark III also boosted continuous shooting (to 5 frames per second), added live view and a whole range of features debuted in the (externally and functionally almost identical) EOS-1D Mark III. Superb image qualityat lower ISOs mean it's still a highly capable studio camera, even if Nikon's D3X stole its 'ultimate DSLR' crown.